KR102138353B1 - Conductive support member and method for manufacturing the same - Google Patents

Abstract

The welding arm 10 is provided with a tip electrode 11, a holder 12, and a shank 20. The shank 20, which is a conductive support member, includes a Cu matrix and a second phase dispersed in the Cu matrix and comprising a Cu-Zr-based compound, and Cu-xZr (where x is atomic% of Zr, 0.5≤ and an inner circumferential portion 21 having an alloy composition of x≤16.7) and a metal containing Cu present on the inner circumferential side of the outer circumferential portion 22 and having higher conductivity than the outer circumferential portion 22. .

Description

Conductive support member and method for manufacturing the same

The present disclosure, which is an invention disclosed in the present specification, relates to a conductive support member and a method for manufacturing the same.

Conventionally, as a conductive support member, it is known to use a welding electrode for welding by melting a contact interface by flowing a large current in a short period of time while holding and pressing a steel or aluminum alloy as a welding object. As such an electrode for welding, it has been proposed, for example, to have an electrothermal interference portion having a thermal conductivity smaller than that of the surroundings in the central region of the narrow surface of the opposing electrode (see, for example, Patent Document 1). In addition, an electrode for resistance welding in which an electrode tip formed of tungsten-based steel is embedded in a tip of a shank has been proposed (for example, see Patent Document 2). It is said that the welding electrode can be subjected to resistance welding of a plated steel sheet having high tensile strength.

Patent Document 1: Japanese Patent Publication No. 2009-220168 Patent Document 2: Japanese Patent Publication No. 2007-260686

By the way, the welding electrode may be attached to a welding robot arm and used for welding such as a steel sheet. Such a welding robot arm has a highly conductive electrode tip disposed at the top end, and includes a heat-dissipating holder constituting the welding arm, and a shank that is an energized part interposed between the holder and the electrode tip. Among them, for example, a shank as a conductive support member, etc., is required for high electrical conductivity to increase welding efficiency, and high strength and high hardness to ensure load strength and long-term durability at high temperatures are required. Further, the welding robot arm needs to be further highly electrified and highly hardened, such as an increase in the number of welding points in recent years, but it is still not sufficient in the current situation, and further improvement is required.

The conductive support member and its manufacturing method disclosed in this specification have been made in view of these problems, and the main purpose is to provide one having a higher conductivity and a higher hardness.

As a result of earnest research to achieve the above-mentioned object, the present inventors have a higher conductivity when a copper metal is used as a current collector and an alloy containing a Cu-Zr-based compound in its outer circumference is a composite member made of a strength structure. And that having a higher hardness.

That is, the conductive support member disclosed in the present specification,

Cu phase, and a second phase comprising a Cu-Zr-based compound dispersed in the Cu phase, and an alloy of Cu-xZr (where x is atomic% of Zr and satisfies 0.5≤x≤16.7) Cho, Seong-in,

A metal that is present on the inner circumferential side of the outer circumference and contains Cu and has a higher conductivity than the outer circumference.

It is equipped with.

Moreover, the manufacturing method of the electroconductive support member disclosed in this specification is

A method of manufacturing a conductive support member having an outer circumference and an inner circumference on the inner circumference of the outer circumference and having a higher conductivity than the outer circumference.

Cu-xZr (where x is Zr) is formed by using either Cu or Cu-Zr mother alloy powder or Cu and ZrH ₂ powder, which includes Cu and has a higher conductivity than the outer periphery. Atomic%, and satisfies 0.5≤x≤16.7). The raw powder of the outer circumferential portion is placed on the outer circumferential side of the raw material of the inner circumferential portion, and at a predetermined temperature and a predetermined pressure lower than the process point temperature Sintering process to maintain pressure in the range and to discharge plasma sinter the mixed powder

It is to include.

In the conductive support member disclosed in the present specification and its manufacturing method, a conductive support member having high conductivity and higher hardness can be provided. The reason is estimated as follows. For example, the conductive support member is formed of a material including a Cu matrix having an inner circumference having high conductivity, an outer circumference having high strength, and a second phase containing a Cu-Zr-based compound. It is presumed to exhibit high conductivity at the inner circumferential side and high strength and high hardness at the outer circumferential side. In addition, in the method of manufacturing such a conductive support member, metal powders generally have a high reactivity depending on their elements. For example, Zr powder has high reactivity to oxygen, and is very convenient for handling when used in the atmosphere as a raw material powder. Need attention. On the other hand, Cu-Zr mother alloy powder (for example, Cu 50 mass% Zr mother alloy) or ZrH ₂ powder is relatively stable and easy to handle even in the air. And, by using such a raw material powder, a relatively simple treatment of discharge plasma sintering can produce an outer circumferential portion containing a Cu-Zr-based compound. In addition, since both the outer circumference and the inner circumference are Cu-based materials, there is no significant difference in sintering temperature, and there is a merit that a target object can be obtained by one sintering by discharge plasma sintering (SPS).

1 is an explanatory view showing an example of a welding arm 10 having a shank 20.
2 is an explanatory view of other shanks 20B to 20E.
3 is an explanatory diagram of SPS conditions of Experimental Example 3.
4 is an SEM image of the raw material powders of Experimental Examples 1-3, 3-3, and 4-3.
5 is an X-ray diffraction measurement result of the raw material powders of Experimental Examples 1-3, 3-3, and 4-3.
6 is an SEM-BEI image of a cross section of Experimental Examples 1-4.
7 is a result of measuring the conductivity of the copper alloys of Experimental Examples 1 to 4.
8 is an X-ray diffraction measurement result of Experimental Examples 1-3, 3-3, and 4-3.
9 is an SEM-BEI image of a cross section of Experimental Example 3-3.
10 is a SEM-BEI image and EDX measurement results of the cross section of Experimental Example 3-3.
11 is a SEM-BEI image, a STEM-BF image, an EDX analysis result, and an NBD figure of the cross section of Experimental Example 3-3.
12 is a SEM-BEI image of a cross section of Experimental Example 4-3.
13 is an SEM-BEI image of a cross section of Experimental Example 4 and an elemental map by EDX method.
14 is a TEM-BF image and SAD diagram of the cross section of Experimental Example 4-3.
15 is an explanatory diagram of SPS conditions of the conductive support member of Example 1;
16 is an explanatory diagram of SPS conditions of the conductive support member of Example 2. FIG.
17 is a SEM photograph of a photo and a cross section of the conductive support member of Example 1. FIG.
18 is an XRD measurement result of Example 1.
19 is a SEM-BEI image of a cross section of the outer circumference of Example 1.
20 is a SEM photograph of a photo and a cross section of the conductive support member of Example 2.
21 is an XRD measurement result of Example 2.
22 is a SEM-BEI image of a cross section of the outer circumference of Example 2.
23 is an SEM photograph of a cross section of the boundary portion of the inner and outer circumferences of Examples 1 to 3.

The conductive support member disclosed in this specification will be described with reference to the drawings. 1 is an explanatory view showing an example of a welding arm 10 having a shank 20 as an example of the conductive support member of the present embodiment. This welding arm 10 welds a to-be-welded object, such as a steel plate or an aluminum alloy plate, for example, and may be used for spot welding. The welding arm 10 includes a tip electrode 11 for contacting and dissolving the object to be welded, a holder 12 disposed at the base of the welding robot to receive power, and a tip electrode 11 and holder 12 It is provided with a shank 20 interposed therebetween to supply power to the tip electrode 11 and to hold it. The tip electrode 11 is a member that requires conductivity, high heat stability, and hardness. For example, tungsten, tungsten alloy, molybdenum, molybdenum alloy, Cu-W-based alloy, Cu-Cr-based alloy, and oxygen-free copper (OFC) are used. It may be configured. The housing (socket) of the tip electrode requires high hardness, and may be made of, for example, a Cu-Be-Co alloy. The holder 12 is a member that requires high heat dissipation, high strength, and high hardness, and may be made of, for example, a Cu-Ni-Be-based alloy.

The shank 20 is a member requiring high conductivity, high strength, and high hardness. The shank 20 is provided with an inner circumferential portion 21, an outer circumferential portion 22, and a working layer 24. Moreover, the layer to be processed 24 may be omitted. The shank 20 is formed with a connecting portion (not shown) to which the tip electrode 11 is connected, and a mounting portion not shown to be attached to the holder 12.

The inner circumferential portion 21 is a portion that exists on the inner circumferential side of the outer circumferential portion and has higher conductivity than the outer circumferential portion. The inner circumferential portion 21 is formed of a metal containing Cu. The metal containing Cu may be, for example, a Cu metal, CuW, Al ₂ O ₃ -Cu (alumina-dispersed copper), a Cu-Cr-based alloy, a Cu-Cr-Zr-based alloy, or the like. desirable. The inner peripheral portion 21 may contain an inevitable component (for example, trace amounts of oxygen). The oxygen content is, for example, preferably 700 ppm or less, and may be 200 ppm to 700 ppm. Examples of the inevitable component include Be, Mg, Al, Si, P, Ti, Cr, Mn, Fe, Co, Ni, Zn, Sn, Pb, Nb, Hf, and the like (see Table 1). This inevitable component may be included in a range of 0.01% by mass or less of the whole. The inner periphery portion 21 is preferably higher in conductivity, preferably 80% IACS or higher, more preferably 90% IACS or higher, and even more preferably 95% IACS or higher. In addition, the electrical conductivity is determined by measuring the volume resistance of the copper alloy in accordance with JIS-H0505, calculating the ratio with the annealed pure copper resistance (0.017241 μΩm), and converting it into electrical conductivity (% IACS). In addition, the inner peripheral portion 21 may be about 50 to 80 MHv in terms of Vickers hardness. The inner peripheral portion 21 may have a higher thermal conductivity than the outer peripheral portion 22. Further, the inner circumferential portion 21 may have a shape such as a columnar shape, an elliptical columnar shape, a polygonal shape (including a rectangular shape, a hexagonal shape, etc.), or a linear shape, a bending shape, or an arc shape. Moreover, the inner periphery 21 may be in the center of the shank 20, or may be in a position displaced from the center.

The outer peripheral portion 22 may be a portion having a higher hardness or mechanical strength (tensile strength, etc.) than the inner peripheral portion. The outer circumferential portion 22 includes a Cu matrix and a second phase dispersed in the Cu matrix and containing a Cu-Zr-based compound, wherein Cu-xZr (where x is atomic% of Zr, 0.5≤x≤16.7 It satisfies) alloy composition. This x may be 15.2 or less, or 8.6 or less. The outer peripheral portion 22 is a portion having conductivity and high mechanical strength. In the outer circumferential portion 22, the Cu mother phase and the second phase are separated into two phases, and the second phase may contain Cu ₅ Zr as a Cu-Zr-based compound. Moreover, the inevitable component may also be contained in this outer peripheral part 22. The outer peripheral portion 22 may have a composition shown in Table 1 when Zr is diluted to contain 0.5 at% or more and 8.6 at% or less. Cu ₅ Zr is MHv 585±100 in terms of Vickers hardness. The outer peripheral portion 22, in the alloy composition of Cu-xZr, x is preferably 1.0 or more, more preferably 3.0 or more, and even more preferably 5.0 or more. When x becomes large, that is, Zr increases, mechanical strength, hardness, etc. are further improved, which is preferable. It is preferable that this outer peripheral part has any one or more of the following (1)-(4).

(1) The average particle diameter D50 of the second phase in the cross section is in the range of 1 µm to 100 µm. (2) The second phase has a Cu-Zr-based compound phase in the outer shell, and the central core portion contains a Zr phase with more Zr than the outer shell.

(3) The outer Cu-Zr-based compound phase has a thickness of 40% to 60% of the particle radius, which is the distance between the outermost circumference of the particle and the center of the particle.

(4) The hardness of the outer Cu-Zr-based compound phase is MHv 585±100 in terms of Vickers hardness, and the Zr phase in the core is MHv 310±100 in Vickers hardness.

The Cu mother phase is a phase containing Cu, and may be, for example, a phase containing α-Cu. By this Cu phase, electrical conductivity can be made high and workability can further be improved. This Cu phase does not contain a process phase. Here, it is assumed that the process phase is, for example, a phase containing Cu and a Cu-Zr-based compound. The average particle diameter D50 of the second phase is determined as follows. First, using a scanning electron microscope (SEM), a reflection electron image of a region of 100 to 500 times the cross section of the sample is observed, the diameter of the inscribed circle of the particles contained therein is determined, and this is the diameter of the particle. Then, the particle diameters of all particles present in the field of view are obtained. This is done with respect to a plurality of fields of view (for example, 5 field of view), the cumulative distribution is obtained from the obtained particle diameter, and the median diameter is taken as the average particle diameter D50. In the outer peripheral portion 22, it is preferable that the Cu-Zr-based compound phase contains Cu ₅ Zr. The Cu-Zr-based compound phase may be a single phase, or may be a phase containing two or more types of Cu-Zr-based compounds. For example, a Cu ₅₁ Zr ₁₄ phase single phase, a Cu ₉ Zr ₂ phase single phase, a Cu ₅ Zr phase single phase, or a Cu ₈ Zr ₃ phase single phase may be used, and other Cu-Zr-based compounds (Cu ₅₁ Zr _{14 with the} Cu ₅ Zr phase as the main phase) B. Cu ₉ Zr ₂ , Cu ₈ Zr ₃ ) may be used as floating, and other Cu-Zr-based compounds (Cu ₅₁ Zr ₁₄ or Cu ₅ Zr, Cu ₈ Zr ₃ ) may be used as the main phase of Cu ₉ Zr ₂ . You may do it as an injury. Note that the main phase refers to a phase having the largest abundance ratio (volume ratio or area ratio in the observation region) of the Cu-Zr-based compound phase, and the floating phase refers to a phase other than the main phase among the Cu-Zr-based compound phase. Since the Cu-Zr-based compound phase has a high Young's modulus and hardness, for example, the presence of this Cu-Zr-based compound phase can further increase the mechanical strength of the shank 20. In the outer peripheral portion 22, the Zr phase included in the second phase may be, for example, Zr of 90 at% or higher, 92 at% or higher, or 94 at% or higher. In addition, the second phase may be formed with an oxide film formed on the outermost side. The presence of this oxide film may suppress the diffusion of Cu into the second phase. In addition, a number of concave fine particles may be formed in the twin core of the second phase. The fine particles are in the form of Zr, and the one formed in the convex portion may be a Cu-Zr-based compound. It is presumed that, with such a structure, for example, the conductivity can be further increased while the mechanical strength can be further increased. The outer peripheral portion 22 may be formed by discharging plasma sintering of a copper powder and a Cu-Zr mother alloy or a copper powder and a ZrH ₂ powder having a sub-step composition. The discharge plasma sintering will be described later in detail. The sub-process composition may be, for example, a composition containing Zr at least 0.5 at% and at least 8.6 at%, and the other being Cu.

The outer peripheral portion 22 is preferably conductive, for example, preferably 20% IACS or more, more preferably 30% IACS or more, and even more preferably 40% IACS or more. Moreover, in this outer peripheral part 22, the value of the Vickers hardness of the second phase Cu-Zr-based compound is preferably 300 MHv or more, more preferably 500 MHv or more, and even more preferably 600 MHv or more. In addition, the outer peripheral portion 22 may have a radius ratio of 1:1 to 3:1 with the inner peripheral portion 21. In addition, the inner peripheral portion 21 and the outer peripheral portion 22 may be joined by diffusion of Cu during sintering.

The to-be-processed layer 24 is a layer which is easy to process the outer shape, and is formed on the outer circumferential surface further outside the outer circumferential portion 22. With this work layer 24, it can be solved that the outer circumferential portion 22 is too hard to be externally processed. The processing layer 24 may be, for example, Cu metal or brass, CuW, Al ₂ O ₃ -Cu (alumina-dispersed copper), Cu-Cr-based alloy, Cu-Cr-Zr-based alloy, or the like. The thickness of the to-be-processed layer 24 may be 0.1 mm or more and 5 mm or less. In addition, it is more preferable that this to-be-processed layer 24 contains Cu, and is sintered simultaneously with the inner peripheral portion 21 and the outer peripheral portion 22. By reducing the number of times of sintering, it is possible to reduce the number of process steps and suppress the firing energy.

The shape of the shank 20 is not particularly limited, but may be, for example, a columnar shape, an elliptical columnar shape, a polygonal shape (including a rectangular shape, a hexagonal shape, etc.), a columnar shape, a straight line shape, or a bent shape. You may do it. The shank 20 can be formed into an arbitrary shape according to the application or the like. In addition, as shown in the shank 20B of FIG. 2, an intermediate portion 23 is formed between the inner circumferential portion 21 and the outer circumferential portion 22 to show their intermediate properties, and from the center to the outer circumferential direction, multiple stages are formed. The conductivity, mechanical strength, hardness, etc. may be inclined red or gradient. In addition, as shown in the shank 20C of FIG. 2, the inner circumferential portion 21 may have a hollow shape in which an internal space 25, which is a refrigerant passage such as a pipe for water cooling, is formed. In addition, as shown in the shank 20D of FIG. 2, for example, an inner space 25 of a cylindrical or sectional polygon (such as a rectangle) is formed inside the inner circumferential portion 21, and a distribution pipe 26 is installed therein. It may be of a double tube structure. In addition, as shown in the shank 20E of FIG. 2, a distribution structure in which a cylindrical or sectional polygonal inner space 25 is formed inside the inner periphery 21 and a partition plate 27 is installed in the space is provided. It may be formed.

Next, a method of manufacturing the conductive support member of the present embodiment will be described. This manufacturing method is a method of manufacturing a conductive support member having an outer circumferential portion and an inner circumferential portion which is present on the inner circumferential side of the outer circumferential portion and has a higher conductivity than the outer circumferential portion. This manufacturing method may include (a) a powdering step of obtaining a mixed powder of raw materials, and (b) a sintering step of discharge plasma sintering (SPS: Spark Plasma Sintering) using the raw powder. Moreover, you may prepare a powder separately and omit a powdering process.

(a) powdering process

In this step, the copper powder and the Cu-Zr parent alloy, or the copper powder and the ZrH ₂ powder are Cu-xZr (where x is atomic% of Zr (hereinafter referred to as at%)), and 0.5≤x≤8.6 Weight), and pulverized and mixed in an inert atmosphere until the average particle diameter D50 is in the range of 1 µm or more and 500 µm or less to obtain a mixed powder. In this step, the raw material (copper powder and Cu-Zr mother alloy or copper powder and ZrH ₂ powder) may be weighed with an alloy composition of Cu-xZr (0.5 at% ≤ x ≤ 16.7 at%). The mixed powder may be compounded so as to have any one of the sub-process composition (0.5 at%≤x<8.6 at%), the process composition (x=8.6 at%), and the hyper-process composition (8.6 at%<x≤16.7). The copper powder, for example, preferably has an average particle diameter of 180 µm or less, more preferably 75 µm or less, and even more preferably 5 µm or less. The average particle diameter is set to a D50 particle diameter measured using a laser diffraction particle size distribution measuring device. Moreover, it is preferable that copper powder consists of copper and an inevitable component, and oxygen-free copper (JIS C1020) is more preferable. Examples of the inevitable components include Be, Mg, Al, Si, P, Ti, Cr, Mn, Fe, Co, Ni, Zn, Sn, Pb, Nb, Hf, and the like. This inevitable component may be included in a range of 0.01% by mass or less of the whole. In this step, it is preferable to use a Cu-Zr mother alloy having a Cu content of 50% by mass as a raw material for Zr. This Cu-Zr alloy is preferable because it is relatively chemically stable and easy to work. The Cu-Zr mother alloy may be an ingot or metal piece, but finer metal particles are preferable because pulverization and mixing are easy. The Cu-Zr alloy, for example, preferably has an average particle diameter of 250 µm or less, and more preferably 20 µm or less. Moreover, in this process, it is preferable to use the process ZrH ₂ powder as a raw material of Zr. This ZrH ₂ powder is preferable because it is relatively chemically stable and easy to work in the air. The ZrH ₂ powder, for example, preferably has an average particle diameter of 10 μm or less, and preferably 5 μm or less.

In this process, Cu-xZr (0.5 at% ≤ x ≤ 16.7 at%) is mixed in an alloy composition, but is, for example, in the range of 8.6 at% ≤ x ≤ 16.7 at% or 8.6 at% ≤ x ≤ 15.2 at%. The range may be any one of 15.2 at%≤x≤16.7 at% and 5.0 at%≤x≤8.6 at%. When the content of Zr is large, mechanical strength tends to increase. Further, the alloy composition may be in a range of 0.5 at% ≤ x ≤ 5.0 at%. When the content of Cu is large, conductivity tends to increase. That is, in this step, Cu _{1 - X} Zr _X (0.005 ≤ _X ≤ 0.167) is mixed with an alloy composition, but may be in the range of 0.05 ≤ _X ≤ 0.086, for example, or in the range of 0.086 ≤ X ≤ 0.167. When the content of Zr is large, mechanical strength tends to increase. Further, the alloy composition may be in the range of 0.005≤X≤0.05. When the content of Cu is large, conductivity tends to increase. In this step, the copper powder, the Cu-Zr mother alloy or the ZrH ₂ powder, and the grinding medium may be mixed and pulverized in a sealed container. In this step, it is preferable to mix and crush with a ball mill, for example. The grinding media are agate (SiO ₂ ), alumina (Al ₂ O ₃ ), silicon nitride (SiC), zirconia (ZrO ₂ ), stainless steel (Fe-Cr-Ni), chromium steel (Fe-Cr), cemented carbide (WC-Co) ) And the like, but are not particularly limited, from the viewpoint of preventing high hardness, specific gravity, and foreign matter mixing, it is preferably a Zr ball. In addition, the inside of the sealed container is set to an inert atmosphere such as nitrogen, He, or Ar. The treatment time for the mixing and grinding may be determined empirically so that the average particle diameter D50 is in the range of 1 µm to 500 µm. This processing time may be, for example, 12 hours or longer, or 24 hours or longer. Moreover, as for the mixed powder, the range of the average particle diameter D50 is 100 micrometers or less is preferable, the range of 50 micrometers or less is more preferable, and the range of 20 micrometers or less is more preferable. The mixed powder after mixing and pulverization is preferable because the smaller the particle size, the more uniform a copper alloy can be obtained. The mixed powder obtained by pulverizing and mixing may include, for example, Cu powder or Zr powder, or may include Cu-Zr alloy powder. The mixed powder obtained by pulverizing mixing may be alloyed at least partially in the process of pulverizing mixing, for example.

(b) Sintering process

In this process, the raw material of the inner circumferential portion is disposed, the mixed powder raw material of the outer circumferential portion is disposed on the outer circumferential side, and the mixture powder is pressurized and maintained at a predetermined temperature and a predetermined pressure lower than the process point temperature, and the mixed powder is discharge plasma sintered. do. Moreover, you may arrange|position the raw material of a to-be-processed layer further outside the outer peripheral part, and also include this, and sintering at this process may be sufficient. In addition, as in the shank 20B of FIG. 2, a raw material of an intermediate portion having intermediate characteristics between the inner and outer circumferential portions may be disposed to sinter it. In addition, in this step, the inner space for circulating the cooling medium may be formed in the inner periphery by filling the raw material for space formation that can be removed later and removing the raw material for space formation after sintering (see FIGS. 2B to 2D). . In this step (b), the raw material may be inserted into a graphite die, and discharge plasma sintering may be performed in vacuum. The raw material of the inner peripheral portion may be a powder, a molded body, or a sintered body, but is more preferably a powder. This is because it can be sintered together with the outer peripheral powder. The raw material of the inner periphery may be a powder such as Cu metal, CuW, Al ₂ O ₃ -Cu (alumina dispersed copper), Cu-Cr-based alloy, or Cu-Cr-Zr-based alloy. When the inner circumferential portion and the outer circumferential portion are powders, for example, the inner circumferential portion of the partition plate is filled with powder of the inner circumferential portion, and the outer circumferential portion is filled with raw powder of the outer circumferential portion, before the SPS sintering treatment It may be removed. As the raw material for the outer peripheral portion, a powder having an alloy composition of Cu-xZr (0.5 at% ≤ x ≤ 16.7 at%) obtained in the powdering step is used.

The vacuum condition at the time of sintering may be 200 Pa or less, for example, 100 Pa or less, or 1 Pa or less. In this step, discharge plasma sintering may be performed at a temperature lower than the process point temperature of 400°C to 5°C (for example, 600°C to 950°C), and discharge plasma sintering may be performed at a temperature of 272°C to 12°C lower than the process point temperature. You may do it. Further, the discharge plasma sintering may be performed so that the temperature is 0.9 Tm°C or lower (Tm (°C) is the melting point of the alloy powder). The pressing conditions for the raw materials may be in a range of 10 MPa or more and 100 MPa or less, or in a range of 60 MPa or less. In this way, a dense copper alloy can be obtained. Moreover, 5 minutes or more are preferable, 10 minutes or more are more preferable, and 15 minutes or more are more preferable as a pressurization holding time. Moreover, as for the pressure holding time, the range of 100 minutes or less is preferable. As discharge plasma conditions, for example, it is preferable to flow a direct current in the range of 500 A or more and 2000 A or less between the die and the base plate.

According to the electroconductive support member (shank 20) of this embodiment demonstrated in detail above, and its manufacturing method, what has high electrical conductivity and higher hardness can be provided. The reason is estimated as follows. For example, the conductive support member is formed of a material including a Cu matrix having an inner circumference having high conductivity, an outer circumference having high strength, and a second phase containing a Cu-Zr-based compound. It is presumed to exhibit high conductivity at the inner circumferential side and high strength and high hardness at the outer circumferential side. In addition, in the method of manufacturing such a conductive support member, metal powders generally have a high reactivity depending on their elements. For example, Zr powder has high reactivity to oxygen, and is very convenient for handling when used in the atmosphere as a raw material powder. Need attention. On the other hand, the Cu-Zr mother alloy powder (for example, the Cu 50 mass% Zr mother alloy) and the ZrH ₂ powder are relatively stable and easy to handle even in the air. And, by using such a raw material powder, a relatively simple treatment of discharge plasma sintering can produce an outer circumferential portion containing a Cu-Zr-based compound. In addition, since the outer circumferential portion, the inner circumferential portion, and further the layer to be processed are Cu-based materials, there is no significant difference in the sintering temperature, and the target object can be obtained by one sintering by discharge plasma sintering (SPS). In addition, the conductive support member can be produced by a relatively simple treatment of discharge plasma sintering using a relatively chemically stable Cu-Zr mother alloy powder (for example, a Cu 50 mass% Zr mother alloy) or ZrH ₂ powder.

Moreover, it goes without saying that the conductive support member of the present disclosure and its manufacturing method are not limited to the above-described embodiments at all, and can be implemented in various aspects as long as they fall within the technical scope of the present disclosure.

Example

Hereinafter, an example in which the conductive support member is specifically manufactured will be described as an example. First, first, the contents examined about the properties of the Cu-Zr-based material in the outer circumference will be described as an experimental example. In addition, Experimental Examples 3-1 to 3-3 and 4-1 to 4-3 correspond to Examples, and Experimental Examples 1-1 to 1-3 and 2-1 to 2-3 correspond to Reference Examples.

[Experimental Example 1 (1-1 to 1-3)]

As a powder, a Cu-Zr-based alloy powder produced by a high pressure Ar gas atomization method was used. The alloy powder had an average particle diameter D50 of 20 to 28 µm. The content of Zr in the Cu-Zr-based alloy powders is 1 at%, 3 at%, and 5 at%, respectively, and the alloy powders of Experimental Examples 1-1 to 1-3 were used. The particle size of the alloy powder was measured using a laser diffraction particle size distribution analyzer (SALD-3000J) manufactured by Shimadzu Corporation. The oxygen content of this powder was 0.100 mass%. The SPS (discharge plasma sintering) as a sintering process was performed using a discharge plasma sintering apparatus (Model: SPS-210LX) manufactured by SPS Syntex Co., Ltd. 40 g of powder was placed in a graphite die having a cavity having a diameter of 20 mm×10 mm, DC pulse energization of 3 kA to 4 kA was performed, a heating rate of 0.4 K/s, and a sintering temperature of 1173 K (about 0.9 Tm; Tm is The alloy alloy melting point), holding time 15 min, and pressurization 30 MPa were produced copper alloys (SPS materials) of Experimental Examples 1-1 to 1-3. Moreover, what was produced by this method is collectively referred to as "Experimental Example 1".

[Experimental Example 2 (2-1 to 2-3)]

Using commercially available Cu powder (average particle diameter D50=33 μm) and commercially available Zr powder (average particle diameter D50=8 μm), the content of Zr in Cu-Zr-based alloy powder is 1 at%, 3 at%, 5 at It was blended so as to be %, and the alloy powders of Experimental Examples 2-1 to 2-3 were used. After CIP molding was performed under the conditions of 20°C and 200 MPa, the copper alloy obtained was subjected to Experimental Example 2 (2-1 to 2-3) through the same process as in Experimental Example 1. In Experimental Example 2, the treatment was performed in an Ar atmosphere.

[Experimental Example 3 (3-1 to 3-3)]

The commercially available Cu powder (average particle diameter D50=1 µm) and a commercially available Cu-50 mass% Zr alloy were used for mixing and grinding for 24 hours with a ball mill using a Zr ball. The average particle diameter D50 of the obtained powder was 18.7 µm. The content of Zr in the Cu-Zr-based alloy powders was formulated to be 1 at%, 3 at%, and 5 at%, respectively, to obtain alloy powders of Experimental Examples 3-1 to 3-3. Using this powder, the copper alloy obtained through the same steps as in Experimental Example 1 was used as Experimental Example 3 (3-1 to 3-3). 3 is an explanatory diagram of SPS conditions in Experimental Example 3.

[Experimental Example 4 (4-1 to 4-3)]

The commercially available Cu powder (average particle diameter D50 = 1 µm) and the commercially available ZrH ₂ powder (average particle diameter D50 = 5 µm) were used for mixing and grinding for 4 hours with a ball mill using a Zr ball. Using the obtained powder, the Zr content of the Cu-Zr-based alloy powder was formulated to be 1 at%, 3 at%, and 5 at%, respectively, to obtain alloy powders of Experimental Examples 4-1 to 4-3. Using this powder, the copper alloy obtained through the same steps as in Experimental Example 1 was used as Experimental Example 4 (4-1 to 4-3).

(Observation of micro tissue)

The microstructure was observed using a scanning electron microscope (SEM), a scanning transmission electron microscope (STEM), and a nanobeam electron beam diffraction method (NBD). For SEM observation, secondary electron images and reflected electron images were taken at an acceleration voltage of 2.0 kV using Hitachi High-Technologies S-5500. For the TEM observation, a BF-STEM image or a HAADF-STEM image was taken at an acceleration voltage of 200 kV using JEM-2100F manufactured by Nihon Denshi, and nano-electron beam diffraction was performed. Further, elemental analysis using EDX (JED-2300T manufactured by Nippon Denshi) was conducted appropriately. The measurement sample was prepared by ion milling an ion source with argon and an acceleration voltage of 5.5 kV using a SM-09010 Cross Section Polisher (CP) manufactured by Nihon Denshi.

(XRD measurement)

The compound phase was identified by X-ray diffraction using Co-Kα rays. For the XRD measurement, RINT RAPIDII manufactured by Rigaku Corporation was used.

(Electrical property evaluation)

The electrical properties of the SPS material and the fresh material of the obtained experimental example were examined by measuring the probe-type conductivity at room temperature and measuring the electric resistance of a terminal method at a length of 500 mm. The electrical conductivity was measured in terms of the electrical conductivity (% IACS) by measuring the volume resistance of the copper alloy in accordance with JISH0505, and calculating the ratio with the annealed pure copper resistance (0.017241 μΩm). For conversion, the following formula was used. Conductivity γ (% IACS)=0.017241 ÷ volume resistance ρ×100.

(Characteristic evaluation of Cu-Zr-based compound phase)

The Young's modulus E and the hardness H by the nano-indentation method were measured for the Cu-Zr-based compound phase contained in the copper alloy of Experimental Example 3. As the measuring device, a Nano Indenter XP/DCM manufactured by Agilent Technologies was used, and XP and an indenter made of diamonds were used as a Berkovich type of indenter head. In addition, Test Works 4 of Agilent Technologies was used as the analysis software. For the measurement conditions, the measurement mode was CSM (continuous stiffness measurement), the excitation vibration frequency was 45 Hz, the excitation vibration amplitude was 2 nm, the distortion rate was 0.05 s ^-1 , the indentation depth was 1000 nm, and the measurement score N was 5, The measurement point interval was 5 µm, the measurement temperature was 23°C, and the standard sample was made of fused silica. The sample is cross-sectioned by a cross-section polisher (CP), and the sample stand and the sample are heated at 100° C. for 30 seconds using a heat-melting adhesive to fix the sample to the sample stand. The Young's modulus E on the Zr-based compound and the hardness H by the nanoindentation method were measured. Here, the average value measured by five points was set as Young's modulus E and hardness H by the nanoindentation method.

(Consideration of materials constituting the outer peripheral part)

First, raw materials were examined. 4 is an SEM image of the raw material powder of (a) Experimental Example 1-3, (b) Experimental Example 3-3, and (c) Experimental Example 4-3. The raw material powder of Experimental Example 1-3 was spherical, and the raw material powders of Experimental Examples 3-3 and 4-3 were coarse teardrop type Cu powder and fine spherical CuZr powder or ZrH ₂ powder, respectively. 5 is an X-ray diffraction measurement result of the raw material powders of Experimental Examples 1-3, 3-3, and 4-3. In the raw material powder of Experimental Example 1-3, it was Cu phase, Cu ₅ Zr compound phase, and Unknown phase. In the raw material powder of Experimental Example 3-3, it was Cu phase, CuZr compound phase, and Cu ₅ Zr compound phase. In addition, in the raw material powder of Experimental Example 4-3, the Cu phase, the ZrH ₂ phase, and the α-Zr phase were _double structures. The SPS material examined below was produced using such a powder.

6 is an SEM-BEI image of a cross section of Experimental Examples 1-4. In Experimental Example 1, two phases of Cu and a Cu-Zr-based compound (mainly Cu ₅ Zr) did not include a process phase, and had a structure in which crystals having a size of 10 µm or less were dispersed in a cross-section. In Experimental Example 1, the particle size of the Cu-Zr-based compound when viewed in cross section was small and had a relatively uniform structure. On the other hand, in Experimental Examples 2 to 4, a relatively large second phase was dispersed in the α-Cu matrix. 7 is a result of measuring the conductivity of the copper alloys of Experimental Examples 1 to 4. Although the copper alloys of Experimental Examples 1 to 4 had the above-described differences in structure, the tendency of the Zr content and conductivity was not significantly different from the copper alloys of Experimental Examples 1 to 4. It was estimated that this is because the conductivity of the copper alloy depends on the Cu phase, and there is no structural difference in the Cu phase. In addition, since the mechanical strength of the copper alloy is considered to depend on the Cu-Zr-based compound phase and has these, it was estimated that the mechanical strengths also show relatively high values for Experimental Examples 2 to 4. 8 is an X-ray diffraction measurement result of Experimental Examples 1-3, 3-3, and 4-3. As shown in Fig. 8, in Experimental Examples 1 and 3 to 4, the α-Cu phase, the Cu ₅ Zr compound phase, and the Unknown phase were detected, and it was presumed to have these complex structures. This indicates that the structure of the SPS material is the same even though the starting materials of the powders are different. The structures of the SPS materials of Experimental Examples 1-1, 1-2, 3-1, 3-2, 4-1, and 4-2 had different X-ray diffraction intensities depending on the amount of Zr, respectively. It was the same double structure as the SPS material shown.

Next, Experimental Example 3 was examined in detail. 9 is an SEM-BEI image of a cross section of Experimental Example 3-3. The average particle diameter D50 of the second phase was determined from the captured SEM photograph. As for the average particle diameter of the second phase, a reflection electron image in a region of 100 to 500 times was observed, the diameter of the inscribed circle of the particles included in the image was obtained, and this was used as the diameter of the particles. Then, the particle diameters of all particles present in the field of view were determined. It was supposed to do this with respect to 5 fields of view. The cumulative distribution was calculated|required from the obtained particle diameter, and the median diameter was made into the average particle diameter D50. As shown in the SEM photograph of FIG. 10, it can be seen that the copper alloy of Experimental Example 3 has an average particle diameter D50 of the second phase in a range of 1 µm to 100 µm when viewed from a cross section. In addition, it was estimated that the second phase had an oxide film formed on the outermost side of the coarse particles. In addition, it can be seen that a large number of fine particles and twins are formed in the core of the second phase. 10 is a SEM-BEI image and EDX measurement results of the cross section of Experimental Example 3-3. 11 is a SEM-BEI image, a STEM-BF image, an EDX analysis result, and an NBD figure of a cross section of Experimental Example 3-3. From the results of the elemental analysis, it can be seen that the second phase has a Cu-Zr-based compound phase containing Cu ₅ Zr in its outer shell, and contains a Zr-rich Zr phase in which Cu is 10 at% or less in the core portion.

For this Zr phase and Cu-Zr-based compound phase, hardness H by nanoindentation was measured. The Young's modulus E and the hardness H were performed by multi-point measurement, and after measurement, the measurement point pressed into the Zr phase by SEM observation was extracted. From the measurement results, Young's modulus E and hardness H by the nanoindentation method were determined. As a result, the Young's modulus of the Zr phase was 75.4 GPa as an average, and the hardness H was 3.37 GPa as an average (Vickers hardness converted value MHv = 311). It can be seen that the Cu-Zr-based compound phase has a Young's modulus E of 159.5 GPa and a hardness H of 6.3 GPa (Vickers hardness conversion value MHv=585), which is different from the Zr phase. As the conversion at this time, MHv=0.0924×H was used (ISO14577-1 Metallic Materials-Instrumented Indentation Test for Hardness and Materials Parameters Part 1: Test Method, 2002.).

Next, Experimental Example 4 was examined in detail. 12 is an SEM-BEI image of a cross section of Experimental Example 4-3. The average particle diameter D50 of the second phase was determined in the same manner as described above from the SEM image taken. As shown in the SEM photograph of FIG. 12, it can be seen that the copper alloy of Experimental Example 4 had an average particle diameter D50 of the second phase in the range of 1 μm to 100 μm when viewed in cross section. In addition, it can be seen that the second phase has a Cu-Zr-based compound phase containing Cu ₅ Zr in the outer shell of the coarse particles, and contains a Zr-rich Zr phase in the core portion. 13 is an SEM-BEI image of a cross section of Experimental Example 4 and an elemental map by EDX method. As shown in FIG. 13, it was estimated that the central core portion of the second phase is a Zr phase rich in Zr with little Cu and very large Zr. 14 is (a) TEM-BF image of the cross section of Experimental Example 4-3 and (b) SAD figure of Area1, (c) SAD figure of Area2. On the Cu ₅ Zr compound of the SPS material shown in Fig. 14, microstructures having twins therein were observed. Fig. 14(b) is a SAD (Selected Area Diffraction) figure of Area1 in the microstructure shown in Fig. 14(a), and Fig. 14(c) is shown in Fig. 14(a). SAD figure of Area2 in microstructure. Moreover, the limiting field of view aperture was 200 nm. EDX analysis was also performed in the center of these areas. As a result, the microstructure observed in Area 1 is a Zr-rich phase containing 5 at% Cu as in the SPS material of Experimental Example 3, and the three lattice spacings measured are α-Zr phases with a difference of 1.2% or less. Matched the grid spacing. In addition, the compound phase of Area2 was the same Cu ₅ Zr compound phase as the SPS materials of Experimental Examples 1 and 3.

As described above, in Experimental Examples 3 and 4, depending on whether a relatively chemically stable Cu-Zr mother alloy or ZrH ₂ is used as a raw material, an experiment with superior conductivity and mechanical strength is further improved and abrasion resistance is improved by simpler treatment. It turns out that the copper alloy equivalent to Example 1 can be manufactured.

Next, an example in which a conductive support member having an inner peripheral portion and an outer peripheral portion is produced will be described as an example.

[Example 1]

A cylindrical partition plate having a diameter of 10 mm was formed in a graphite die having a cavity having an inner diameter of 26 mm and a height of 10 mm, and 14.0 g of Cu powder (average particle diameter 75 µm) was filled on the inner circumferential side and Cu powder on the outer circumferential side. (Average particle diameter 75 µm) and ZrH ₂ powder were filled with 75.2 g to an alloy composition of Cu-xZr (x=5.0 at%), and the partition plate was removed. A punch was inserted into the graphite die, and SPS sintering was performed using a discharge plasma sintering apparatus (Model: SPS-210LX) manufactured by SPS Syntex Co., Ltd. The SPS sintering was carried out with DC pulse energization of 3 kA to 4 kA, heating rate of 0.4 K/s, sintering temperature of 1153 K (approximately 0.9 Tm; Tm is the melting point of the alloy), holding time of 15 min, and pressurization of 20 MPa, The obtained composite member was referred to as Example 1. 15 is an explanatory diagram of SPS conditions of the conductive support member of Example 1. FIG.

[Examples 2 to 4]

Example 2 was obtained through the same process as in Example 1, except that the composition of the outer periphery was such that the Cu powder (average particle diameter 75 µm) and the ZrH ₂ powder were alloy compositions of Cu-xZr (x=8.6 at%). I made it. 16 is an explanatory diagram of SPS conditions of the conductive support member of Example 2. FIG. In addition, Example 1 except that the composition of the outer circumference was Cu powder (average particle diameter 75 µm) and the ZrH ₂ powder became the alloy composition of Cu-xZr (x=15.2 at%), and a round bar of pure copper was used as the inner circumference. The obtained member was set as Example 3 through the same process as. In addition, Example 1 except that the composition of the outer circumference was Cu powder (average particle diameter 75 µm) and the ZrH ₂ powder became the alloy composition of Cu-xZr (x=16.7 at%), and a round bar of pure copper was used as the inner circumference. The obtained member was set as Example 4 through the same process as.

[Comparative Example 1]

After dissolving and casting a Cu-Be-Co-based alloy having 1.90% by mass of Be, 0.20% by mass of Co, and Cu as the balance, cold rolling and solution treatment were performed to compare the same shape as in Example 1. It was set as Example 1.

(Measurement of conductivity and hardness)

The conductivity was measured for the inner and outer peripheries. In addition, as described above, the hardness of the Cu-Zr compound particles of the inner and outer circumferential portions was measured, and the Vickers hardness conversion value was obtained in the same manner as in the above Experimental Example.

(Results and discussion)

17 is a SEM photograph of a photo and a cross section of the conductive support member of Example 1. FIG. 18 shows the XRD measurement results of Example 1. 19 is a SEM photograph of a cross section of the outer circumferential portion of Example 1. 20 is a SEM photograph of a photo and a cross section of the conductive support member of Example 2. FIG. 21 shows the XRD measurement results of Example 2. 22 is a SEM photograph of a cross section of the outer circumferential portion of Example 2. 23 is a SEM photograph of a cross section of the boundary portion of the inner and outer circumferences of Examples 1 to 3, and FIG. 23A is Example 1, FIG. 23B is Example 2, FIG. 23C is Example 3, and FIG. 23D is Example It is an enlarged photograph of the grain boundary of 3. In addition, Table 2 shows the details of the samples of Examples 1 and 2, the conductivity of the inner and outer portions (% IACS), and the converted value of Vickers hardness (MHv). In addition, in Table 3, the conductivity, Vickers hardness, and Young's modulus of Comparative Example 1 together with the conductivity, Vickers hardness, and Young's modulus of the entire outer circumferential portion and the Zr compound portion of Examples 1 to 4 are collectively shown. 17 and 20, it was possible to form a member having an inner circumference and an outer circumference through the above steps. It can be seen that the conductivity of the inner peripheral portions of Examples 1 and 2 is 99% IACS and has high conductivity. In addition, the electrical conductivity of the outer peripheral portions of Examples 1 and 2 was 53% IACS and 32% IACS, respectively, and it was found that they had sufficient conductivity. The Vickers hardness conversion values of Examples 1 and 2 were 67 MHv and 76 MHv, respectively, in the inner circumference, while the Cu-Zr-based compounds in the outer circumference were all high hardness of 670 MHv or higher.

In addition, in Examples 1 and 2, as shown in FIGS. 18 and 21, X-ray diffraction peaks of Cu and a Cu-Zr-based compound (Cu ₅ Zr) can be obtained, and as shown in FIGS. 19 and 22. , The structure of the outer periphery was the same as the contents reviewed in the experimental example, and included a Cu phase and a second phase dispersed in the Cu phase and containing a Cu-Zr-based compound. Further, as shown in Table 3, in Examples 1 to 4, as the content of Zr increased, the overall conductivity tended to decrease, but since the content of the Zr compound having a high Vickers hardness increased, the hardness and It was estimated that the intensity was higher. In addition, in all the sintered bodies shown in Figs. 23A to C, the outer circumferential portion (left) is a phase including the Cu matrix phase and the second phase of the Cu-Zr compound (Cu ₅ Zr), and the inner circumferential portion (right) is the Cu phase. As shown in Fig. 23, as the amount of Zr added increased, the amount of the Cu ₅ Zr compound phase on the outer circumference that was brightly increased increased, and changed from an uneven dispersion state to an uneven close state. On the contrary, the amount of Cu phase formed around it decreased. In all compositions, traces thought to be oxides were confirmed, but pores were not observed, and it was found that the densification was carried out. Further, as shown in Fig. 23D, also in Example 3, a Cu phase was dotted in the Cu ₅ Zr compound phase in the outer peripheral portion. In addition, between the outer circumferential portion and the inner circumferential portion, the crystal structure is different, and an interface such as a reaction layer that blocks the flow of electric current is not confirmed, but is in close contact with the diffusion layer. In addition, in Example 4, as in the other examples, the outer circumferential portion includes a Cu phase, a second phase dispersed in the Cu matrix, and containing a Cu-Zr-based compound, and the inner circumference is a structure composed of the Cu phase. It has been estimated that such a member is suitable for use, for example, in a shank of a welding member requiring high electric conductivity and high strength, or in a socket of a tip electrode.

In addition, the present invention is not limited to the above-described embodiments at all, and, of course, can be implemented in various aspects as long as it falls within the technical scope of the present invention.

This application is based on Japanese Patent Application No. 2016-234067 filed on December 1, 2016 as a basis for claiming priority, and the contents thereof are all incorporated into this specification by reference.

The present invention can be used in the technical field of a manufacturing member made of a copper alloy.

10: welding arm, 11: tip electrode, 12: holder, 20, 20B, 20C, 20D, 20E: shank, 21: inner periphery, 22: outer periphery, 23: middle, 24: work layer, 25: inner space , 26: distribution hall, 27: partition plate.

Claims (15)

Cu phase, and a second phase comprising a Cu-Zr-based compound dispersed in the Cu phase, and an alloy of Cu-xZr (where x is atomic% of Zr and satisfies 0.5≤x≤16.7) Cho, Seong-in,
A metal that is present on the inner circumferential side of the outer circumference and contains Cu and has a higher conductivity than the outer circumference.
Conductive support member comprising a. The conductive support member according to claim 1, wherein the outer circumferential portion includes the Cu mother phase and the second phase separated into two phases, and the second phase includes Cu ₅ Zr as the Cu-Zr-based compound. The conductive support member according to claim 1 or 2, wherein the outer peripheral portion has any one or more of the following (1) to (4).
(1) The average particle diameter D50 of the second phase in the cross section is in the range of 1 µm to 100 µm.
(2) The second phase has a Cu-Zr-based compound phase on the outer shell, and the central core portion contains a Zr phase with more Zr than the outer shell.
(3) The outer Cu-Zr-based compound phase has a thickness of 40% to 60% of the particle radius, which is the distance between the outermost circumference of the particle and the center of the particle.
(4) The hardness of the outer Cu-Zr-based compound phase is MHv 585±100 in terms of Vickers hardness, and the central core Zr phase is MHv 310±100 in terms of Vickers hardness. According to claim 1 or claim 2, The inner peripheral portion, Cu metal, CuW alloy, Al ₂ O ₃ -Cu (alumina dispersed copper), Cu-Cr-based alloy, Cu-Cr-Zr-based alloy is at least one of A conductive support member that is formed and may contain unavoidable components. The conductive support member according to claim 1 or 2, wherein a softer working layer is formed on the outer circumferential surface of the outer circumferential portion, compared to the outer circumferential portion. The conductive support member according to claim 1 or 2, wherein a coolant flow path is formed in the inner circumference. The conductive support member according to claim 1 or 2, wherein the conductive support member is a member used in the arm portion of the welding electrode and is a shank interposed between the tip electrode and the tip holder to hold the tip electrode. A method of manufacturing a conductive support member having an outer circumference and an inner circumference on the inner circumference of the outer circumference and having a higher conductivity than the outer circumference.
Cu-xZr (where x is Zr) is formed by using either Cu or Cu-Zr mother alloy powder or Cu and ZrH ₂ powder, which includes Cu and has a higher conductivity than the outer periphery. Atomic%, and satisfies 0.5≤x≤16.7). The raw powder of the outer circumferential portion is placed on the outer circumferential side of the raw material of the inner circumferential portion, and at a predetermined temperature and a predetermined pressure lower than the process point temperature Sintering process to maintain pressure in the range and to discharge plasma sinter the mixed powder
Method for producing a conductive support member comprising a. The method for manufacturing a conductive support member according to claim 8, wherein in the sintering step, a Cu-Zr mother alloy having Cu of 50% by mass is used. The method for manufacturing a conductive support member according to claim 8 or 9, wherein in the sintering step, the raw material is inserted into a graphite die and subjected to discharge plasma sintering in vacuum. The method for manufacturing a conductive support member according to claim 8 or 9, wherein in the sintering step, discharge plasma sintering is performed at the predetermined temperature that is 400°C to 5°C lower than the process point temperature. The method for manufacturing a conductive support member according to claim 8 or 9, wherein in the sintering step, discharge plasma sintering is performed at the predetermined pressure in a range of 10 MPa to 60 MPa. The method for manufacturing a conductive support member according to claim 8 or 9, wherein in the sintering step, discharge plasma sintering is performed with a holding time in a range of 10 minutes or more and 100 minutes or less. 10. The method for manufacturing a conductive support member according to claim 8 or 9, wherein in the sintering step, a raw material of a material to be processed softer than the outer periphery is disposed on the outer peripheral surface further outside the outer periphery. The conductive support member according to claim 8 or 9, wherein the conductive support member is a shank that is interposed between the tip electrode and the tip holder and holds the tip electrode as a member used in the arm portion of the welding electrode. Manufacturing method.

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